Generally, an internal combustion engine of a vehicle is equipped with an exhaust system. The exhaust system functions to reduce the noise from the engine while emitting the exhaust out from the engine. To reduce the noise an exhaust silencer is arranged to define a path for the exhaust gas such that the noise is reduced. Furthermore, the exhaust system may also comprise a catalytic converter for converting toxic gases in the exhaust gas to less toxic gases.
Heat from the exhaust gas may be recovered from the exhaust gas and be used for e.g. heating the cabin of the vehicle, the coolant in the radiator, the engine oil or the transmission oil in a so called heat-to-heat device. The recovered heat may also be used to produce electric energy or to provide additional power to the drive line of the vehicle using a heat-to-power device. For recovering the heat from the exhaust gas, a heat exchanger may be located as part of the exhaust system. In such heat exchanger for an internal combustion engine, heat is transferred from exhaust gas to a working media such as a fluid. The heat exchanger can be of various designs, such as tube or plate heat exchangers. However, heat exchangers are bulky, and space conflicts often occur if these heat exchangers are integrated in the exhaust line. Normally, also a bypass is required to switch off the waste heat recovery system at higher engine loads.
EP2733322 describes a heat exchanger for an exhaust system. In EP2733322, there is shown that heat exchanger pipes are arranged along a first path for the exhaust gas and there is also shown a bypass path in which the exhaust gas bypasses the heat exchanger pipes. However, improvements appear to be possible with relation to the heat exchanger efficiency and further also in relation to noise reduction in the bypass path.
Thus, there appear to be room for improvements over prior art exhaust systems having an integrated heat exchanger.